High jugular bulb is defined as dome of internal jugular vein above round window niche or inferior bony annulus, and related with Meniere's disease, tinnitus, sensory neural hearing loss, etc. This is a well known anomaly but rarely witnessed or documented in the literature. This may results in serious hemorrhage at the time of surgery. The authors analyzed the incidence, position, degree of mastoid pneumatization, relationship with adjacent structures in cases with high jugular bulb detected by high resolution temporal bone computed tomography. The following results were obtained : 1) The distance from horizontal semicircular canal to apex of internal auditory canal was no definitive difference between high jugular bulb group and control group. 2) Anterior displacement of lateral sinus and the decreased pneumatization of temporal bone are more identified in high jugular bulb group than control group. 3) Translabyrinthin approach should be performed carefully in the patient with high jugular bulb. 4) Myringotomy should be preformed carefully in the patient with more laterally placed high jugular bulb to cochlea.